Heat pumps use input energy to drive the transport of heat energy from a cold heat source to a warm heat sink, thereby cooling the cold heat source (acting as a cooler) and heating the warm heat sink (acting as a heater). Most conventional heat pumps utilise a compressor driven by an electric motor or other mechanical power source to raise the pressure and temperature of the working fluid. However in the case of absorption heat pumps changes in temperature of absorption liquids or solids are used to cyclically absorb a working fluid at lower pressure and then release it at a higher pressure thereby effectively pumping the working fluid by non-mechanical means but with typically low efficiency. Similarly Vuilleumier cycle heat pumps utilise a high temperature input of heat energy to drive a heat pumping cycle between a cold heat source and warm heat sink, but have not been widely used due to difficulties with economic implementation.
Much energy consumption is for domestic and industrial heating and cooling. Electricity is a common medium by which this power is distributed and is typically a high cost source of energy due to generation and distribution costs that frequently make it several times the cost of an equivalent quantity of heat energy available to them from other sources such as geothermal heat, natural gas, other combustible fuels, solar, nuclear or waste heat sources. It is therefore a primary goal of the current invention to enable an alternative means of heating and cooling that may utilise energy sources that are cheaper than electricity and additionally to provide a method by which mechanical or electrical power may be more economically generated from some sources of energy, or to at least offer the public a useful choice.
Waste heat streams in the form of hot fluids like engine exhausts, cooling fluids and other hot industrial fluids are frequently large in size but uneconomic to exploit, with many existing methods of utilising that energy only able to utilise a relatively small proportion of the heat energy, leaving a large amount of heat energy in the fluid at temperatures still far above ambient temperatures. It is therefore a goal of the invention to offer novel heat pumps and engines that may utilise a larger proportion of the heat energy in a waste heat fluid stream for useful purposes, or to at least offer the public a useful choice.
Refrigeration and heating are frequently provided by means of heat pumps that cyclically compress and expand gaseous working fluids that are also heated and cooled and may undergo phase changes at one or more parts of the thermodynamic cycle. The compression and expansion processes frequently have inefficiencies that reduce overall efficiency. Similarly in engines the compression and expansion processes are often inefficient, reducing engine efficiency. Phase changes in the working fluid in engines and heat pumps may also increase energy losses. It is therefore an object of this invention to offer novel heat pumps and engines that have relatively high efficiencies by means of utilising highly efficient expansion and compression processes, as well as partly or wholly avoiding phase changes in the working fluid, or to at least offer the public a useful choice.
Many applications require heat sources at temperatures over 100° C., frequently provided by the burning fuels or electrical heating. Heat pump usage for high temperature applications is rare due to the lower price of heating fuels compared to electricity used in low efficiency high temperature electrically driven heat pumps. It is therefore an object of this invention to offer novel heat pumps that may be more economic for heating to temperatures in excess of 100° C. using high temperature heat sources or electricity as the energy input, or to at least offer the public a useful choice. Some power sources are intermittent, unreliable or inadequate in size to power a heat pump of required capacity at all times. It is therefore an object of this invention to offer a novel heat pump that may utilise more than one source of energy to power its operation, or to at least offer the public a useful choice.
The operating temperature ranges of many heat pump cycles are heavily dependent upon the critical temperature of the working fluid utilised. This may restrict the temperature range that a heat pump design may operate over. It is therefore an object of this invention to offer a novel heat pump design that may be modified to service a wide range of temperatures, or to at least off the public a useful choice.
Many heat pumps require auxiliary electric heaters to limit ice accumulation from air. It is therefore an object of this invention to offer a novel heat pump in which the de-icing of atmospheric heat exchangers does not require the use of an auxiliary electric heater, or to at least offer the public a useful choice.
Stirling Cycle engines produce mechanical power from heat sources and when driven by a motor may operate as heat pumps in applications such as cryogenic cooling. The Vuilleumier Cycle is a modified Stirling Cycle that operates as a heat pump powered by high temperature heat energy input. To date apart from some niche applications neither Stirling Cycle nor Vuilleumier Cycle have found widespread application due to high costs, weight and bulk, and in some cases unreliability. It is therefore an object of this invention to provide novel engines and heat pumps with higher efficiency and/or lower costs than Stirling and Vuilleumier Cycle machines for many fields of application, or to at least offer the public a useful choice.
A number of inventors have discovered and innovated upon the idea of utilising highly efficient compression and expansion of gaseous working fluids by centrifugal forces within a rotor as thermodynamic processes within both engines and heat pumps. Several inventors have also identified the use of Xenon as a preferred working fluid and some have also identified the benefits of cooling or heating the working fluid while it is undergoing compression or expansion as a way of approximating the ideal isothermal processes of the optimally efficient Carnot cycle. Additionally the benefits of evacuating a casing within which the rotor spins has been recorded. However these inventors failed to teach effective practical means for implementing machines based upon these principles given the extremely high centrifugal stresses created in high speed rotors.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing the preferred embodiment of the invention without placing limitations thereon.
The background discussion (including any potential prior art) is not to be taken as an admission of the common general knowledge.